Human effects on ecosystems

Human influence on climate change and depletion of resources, and its politics

Climate change

Human industrial activity has contributed large amounts of chemicals, notably carbon dioxide (from combustion activity), to the Earth’s atmosphere that is changing the climate in many areas with varying outcomes and intensity, from an overall average increase in temperature.

Aside from CO₂, methane is also a greenhouse gas – that is, it has the potential to increase the Earth’s average temperature. Greenhouse gases are responsible for the Earth being about 33 degrees Celsius warmer than it would be without them.

The issue arises when the otherwise slow, natural development of global weather patterns is significantly sped up by the burning of fossil fuels. The receding of the North Pole ice (from the yellow line):

A seemingly small increase of several degrees Celsius can have vast effects on the Earth’s crop plants, insect pests and wild plants and animals.

For example, the life cycle of many insect pests is tightly regulated by temperature. A very finely tuned heating up or cooling down triggers development and reproduction. The result of warming is a faster life cycle which means that instead of one generation arising yearly, there might be two or three generations arising yearly instead. This poses problems for the protection of crop plants.

Another example is the redistribution of wild animals. Changes in temperature cause migrations towards the poles of the Earth, and increased desertification at the equator. Pollen in North America has been shown to become increasingly allergenic:

The susceptibility of various parts of the world to be desertificated has also been projected:

Overfishing

This killer infographic brings home the point about how much fish stocks have plummeted more than any description could.

Maintaining viable fish stocks is essential to being able to sustain our reliance on fish, especially in parts of the world where it is one of the main sources of food. Fish are also a major part of the aquatic ecosystem on Earth, and are hence part of complex food webs.

Depleted fish stocks in an ecosystem can throw off other species, and even be the end of a specific ecosystem itself. Several actions have been implemented in fisheries to address these pressing issues.

Safe catch limits can be determined scientifically, and ensure that there is a minimum number of fish left in the ecosystem to maintain a long-term balance.

Controls on bycatch involve using catching methods that minimise the targeting and death of other species alongside the target fish.

Protection of pristine habitats ensures that the spawning grounds of fish aren’t disturbed, as well as unexplored areas (much of the oceans remains unexplored) and corals, which have already been impacted by climate change.

Finally, for any of these measures to be effective, monitoring and enforcement are critical to their long term success. People involved in the fishing industries must be monitored to ensure they are following these guidelines, and a monetary incentive is required to make it uneconomical to cheat.

The CITES treaty

CITES is the Convention on International Trade in Endangered Species of Wild Fauna and Flora, or the Washington Convention. It is decades old now, and has been signed by almost the whole world. Its purpose is to ensure that trading plants and animals does not result in their extinction from their original habitat. To this end, it confers different levels of protection to tens of thousands of species.

These are only the recorded transactions, and they approach one million. Traders must take part in a licensing system, and failure to respect the restrictions on specific species e.g. elephants for ivory, can result in various sanctions. Biodiversity is a key consideration in CITES. Since its implementation, it has succeeded in allowing some elephant populations to recover in the wild after banning the trade of ivory.

Issues of economy in certain places like Japan, where bluefin tuna constitutes a major component in it animal trade, can interfere with the restrictions that CITES votes to implement. Politicians can be sent in large delegations to argue for economic points such as wealth, or even the opposite, poverty, to influence the conservation efforts set by the CITES community. Rules are implemented on a two thirds majority basis.

Some species have had success through CITES, such as reptile, amphibian (sold as pets on the internet) and tigers, while others such as the Atlantic bluefin tuna haven’t, due to governments voting against conservation measures at CITES meetings (which take place every 3 years in different cities).

Managing conflicts in sustainability of resources

As seen previously, conservation efforts cannot succeed outside of a deep consideration of the balance between these efforts and the wider human context including local economies, human practices and beliefs, etc. For example, many products of wild animals that are becoming endangered such as rhinos, elephants and tigers are sought solely due to an often, if not always, unfounded but very strong belief that these animal products can heal disease or bring good fortune.

In the case of overfishing, harder questions come up that are often very difficult to compromise on. When humans rely on fish to survive, or when they rely on the income that the fish can bring, arguing for conservation and controls on fishing, or outright bans, is met with deadpan objection – understandably. This is doubly challenging when the negative impacts of their lifestyle or business can only be felt later in time, or elsewhere in the world altogether. A lack of immediate concern and connection to these downsides contributes to an unwillingness or ignorance towards sustainability and conservation.

These Japanese fishermen lost their livelihood following the 2011 tsunami. In extreme conditions and under high pressure, long term considerations, especially those of conserving biodiversity, are easily overlooked. Because the relationships between species across the planet are so complex, subtle and difficult to fully grasp, local people acting on local ecosystems do not feel particularly responsible for the wider implications of the cumulative repercussions of their activities.

The attempts to address overfishing have thus taken into account all viewpoints: that of the fisher, that of conservationists, and indeed that of the larger ecosystem and biosphere. This is why, rather than attempting unrealistic and hard to implement outright bans, they have sought to impose specific and manageable limits on fishing that minimise the use of fish stocks while allowing humans to feed on them and maintain them as a key part of their economy.

Regarding the even greater challenge of global climate change, similar approaches must be taken where measures to alleviate the impact of human activities are also viable for sustaining human needs. For example, instead of banning petrol cars, authorities can tax them to make people themselves want to change their behaviour – see also the carbon tax that seeks to encourage business away from practices that have a large carbon dioxide footprint.

Similarly, better alternatives such as electric cars like the Tesla Model 3 are subsidised by the government (even from the aforementioned carbon tax) to speed up their adoption.

Validating evidence in the scientific process

As you can see, data regarding climate change comes in many different forms and from many different sources obtained in many different ways, so curating it all together in a specific field or to answer one question is a big task.

Humans are still happy to attempt this task, even though it is clearly one for the machines to tackle. Soon enough this will be the case, however for background or at least a history lesson, here is how things run with humans involved.

Scientists strive to publish their work in scientific journals which are ranked based on the popularity of their content in terms of how many new scientists refer back to older work by previous scientists (or sometimes their own previous work!), and carry out the peer review process which attempts to act as quality control on the work submitted for publishing.

Peer review means that scientists in a relevant field to the work submitted comment on the submission. This informs the journal editor in their decision to accept or reject the submission, sometimes subject to new work being added onto the submission, or changes to be made.

The publishing process itself can take as long as months or years to complete, and the top journal which is Nature is a for-profit organisation which fuels this broken system and routinely rejects most of its submissions, even though they are perfectly valid and often end up being published anyway in a “lower” journal. Hence, an artificial hierarchy is established where amazing and groundbreaking work simply does not have space in the limited space of the overly glorified and undeservedly attained top spot that just one journal has, of hundreds of others.

Quite literally scientists are forced to make it their career goal to publish in Nature or Science, and one can see the level of corruption this type of mania can entail. There are cases of withdrawn submissions, outright data fabrication and exaggeration and this type of outrageous outcomes that do nothing but hinder science and scientists.]

Despite this, when it comes to climate change, the amount of research is huge, as it has been a great effort spread over decades, thousands of scientists in different disciplines, very robust data and almost unanimous agreement amongst peers in deeming the evidence valid.

Another sphere of scientist communication (what is one to do with months between publishing and not being allowed to disclose anything prior to publishing to prevent someone else “stealing” the idea?) is conferences. These are meetings, some generic and some very specialised, where scientists in the field deliver presentations and exhibit posters of their latest work, and network with others to catch up with what everyone is up to. This is where one might find out what someone is working on before their work is actually published.